Art of Practicing: part 3: Extreme Conditioning
Have you ever done that experiment where you hold up your arms while someone pushes down on them for while with all their might...then they let go... and your arms fly up, feeling light as a feather. That's the principal behind training under extreme conditions. Athletes do it all the time. And we violinists have been dubbed small motor athletes. I have many times experienced the glorious sensation of ease where the violin seems to play itself after having subjected myself to extreme condition practicing.